LB7 diagnose leaking injector
 

any way of determining which inj. is the faulty one

Scan tool is about the only option you have. Check the balance rates and maybe do some cylinder power balance tests.

scan tool not available to me. thanks though!

You have no other option then.

took mine to a chevy dealer,,cost 78 bucks,,but thats how I found out,,had 3 of the leaking..

You can do a return rate test on the whole system, bank, and individual injector. But the whole process can take all day and you need soeciel fittings and eqiot to do that. Good thing the dealer helped out out with that.